Too late in the year to treat powdery mildew?

[Mike Corazzi]

If you spritz Bonide into a spray bottle of water until the color ....j u ssss ttt..... turns a shade of blue....
....and spritz the tree IN THE EVENING... but ... while it has time to evaporate, mildew will avoid it.

I'm talking OAK which God created as a home for mildew.

 

[bwaynef]

Milk dilluted 1:10 w/ water also treats powdery mildew. As for it being too late, this is about the time of year I start to see it on my trees.

 

[Kadebe]

One of the key causes of mildew seems to be susceptibility of the host plant.
I have a couple garden plants in full sunshine and in a windy spot and they still get it. Plants right next to it never develop issues, same species of plant. Picking off leaves only removes the leaves, not the issue.
I've heard that certain trichoderma fungi might act as a protective measure. Try googling trichoderma viride, usually the other one pops up as well. I forgot its name.

Well, the more I find out about fungi and insects, the more convinced I become that it's mainly to do with the soil. If you have a balanced soil with all the necessary bacteria in a good ratio, you will hardly have any problems. It is already difficult to balance an ordinary plant soil, let alone our inorganic substrate.

 

[penumbra]

Powdery mildew and other fungus and mold problems are common issues on the east coast, particularly from Virginia southwards. I am a bit surprised that it is such an issue in Colorado, but I am sure your climate varies significantly from one place to another.
Certainly not wanting to come off argumentatively, because we all have a track record of what works for us, I have to say that I have tried neem oil from a couple different sources and not found it to be that effective. Obviously this is my experience and I am aware that many people use it to great advantage. My peroxide at a dollar a quart, is a main weapon in my arsenal, aside from the fact that it has so many functions and uses.

 

[Kadebe]

Milk dilluted 1:10 w/ water also treats powdery mildew. As for it being too late, this is about the time of year I start to see it on my trees.

Did you try this? How to use it? Spray it on the plant and after a certain time clean up with water or let it dry?

 

[Deep Sea Diver]

Yet not sure about neem oil vs copper as a longer term preventative. It would be a nice experiment though! .

Imho Hydrogen Peroxide is more of a as it appears treatment for something like powdery mildew. So far our vine maples (which are native) all seem to get this darn disease, despite all efforts to the contrary. The JMs and Tridents rarely do.

Cheers
DSD sends

 

[DrTolhur]

I think you misinterpreted something there.
The statement was more like if the powdery mildew shows up too early in the year.

Right, but "too early" for what? What does too early mean? How do you know if it's too early? Why would it be "too early" for hydrogen peroxide and need to switch to using copper sulphate?

 

[BobbyLane]

Over here leaves are already getting ready for fall...you can spray, but the leaves will be falling off soon anway. id give the tree a winter wash after leaf drop and spray again when the buds swell in spring.

 

[0soyoung]

I am a bit surprised that it is such an issue in Colorado

Indeed, anywhere away from melon growing. I think @ShadyStump must live near Rocky Ford.

our vine maples (which are native) all seem to get this darn disease, despite all efforts to the contrary. The JMs and Tridents rarely do.

In my area it is deciduous azaleas, deciduous azaleas, deciduous azaleas, deciduous azaleas, as well as big leaf, Douglas, and Norway maples. None of my JMs (palmatum, shirasawanum, and japonicum) do. Further, it is 'only' in September that the rather specific conditions for downy mildew occur in our part of the world.

An interesting aside is that there are no native vine maples on the area islands, including Vancouver island (viable maple seeds don't float, so the species apparently didn't appear in the area before the islands became islands), though we tree-lovers have planted them here and there, as have I. Regardless, they don't seem to be particularly susceptible in my environs.

 

[ShadyStump]

Powdery mildew and other fungus and mold problems are common issues on the east coast, particularly from Virginia southwards. I am a bit surprised that it is such an issue in Colorado, but I am sure your climate varies significantly from one place to another.
Certainly not wanting to come off argumentatively, because we all have a track record of what works for us, I have to say that I have tried neem oil from a couple different sources and not found it to be that effective. Obviously this is my experience and I am aware that many people use it to great advantage. My peroxide at a dollar a quart, is a main weapon in my arsenal, aside from the fact that it has so many functions and uses.

You don't sound argumentative at all. No worries.

I've never seen powdery mildew on native plants, and, yes, the mountains create an enormous range of micro climates. It does seem to be an issue all over the state though.
My guess is that it survives in shadowy maintain sides and canyons where it doesn't get the direct sun so stays wetter longer. Then when we artificially create a wet area with watering, spores blown in from a distance grab hold and go nuts.
I'd wager there are 1000s of different strains adapted to different environments, and the ones around here are fast growers. The neem works here because it's relatively hot and dry during the day over summer, but much cooler at night when the mildew grows. If you water in the morning, it dries out enough that the milder doesn't have as much of a chance, but if you water in the evening you just added moist to the cool, and the mildew takes off.

Right, but "too early" for what? What does too early mean? How do you know if it's too early? Why would it be "too early" for hydrogen peroxide and need to switch to using copper sulphate?

Without going back to read the exact post again, I believe just meaning spotting the powdery mildew early in the season. If you do, hit it hard, probably the copper, and keep up on it with preventative measures.

No issues with any of my trees yet

Scratch that. You bastards got me going and I just looked at my Chicago fig.
Trying the peroxide this time. We'll see how it does.

 

[ShadyStump]

I think @ShadyStump must live near Rocky Ford

Ooo, close, but not close enough. That's a couple hours drive East of me.
Yet they still important our mellons from California. What gives?

Try Cañon City.

 

[Firstflush]

@ShadyStump Out of curiosity are you using cold pressed neem making your own mix or ready to use products?

 

[bwaynef]

Did you try this? How to use it? Spray it on the plant and after a certain time clean up with water or let it dry?

I have. Sprayed it on PM on a crape myrtle's leaves and sprayed it again 4-5 days later.

 

[ShadyStump]

@ShadyStump Out of curiosity are you using cold pressed neem making your own mix or ready to use products?

It's a ready to use, just add to water stuff. I'm not at home at the moment, but I'll go find it when I get home and check the details.

 

[Firstflush]

It's a ready to use, just add to water stuff. I'm not at home at the moment, but I'll go find it when I get home and check the details.

So just an FYI, the reason you are not seeing results with neem oil is because you may not be using cold pressed. If your label says “hydrophobic extract” it is just like any other kitchen oil. The active ingredient, azadirachtin, has been removed and sold as another product. Azadirachtin is actually the pest killer. The azadirachtin is present when you use cold pressed neem. HUGE difference in pest control results.

 

[ShadyStump]

So just an FYI, the reason you are not seeing results with neem oil is because you may not be using cold pressed. If your label says “hydrophobic extract” it is just like any other kitchen oil. The active ingredient, azadirachtin, has been removed and sold as another product. Azadirachtin is actually the pest killer. The azadirachtin is present when you use cold pressed neem. HUGE difference in pest control results.

That's good to know.
Got home later than expected and forgot to go check the bottle. I'll try and remember in the morning.

 

[ShadyStump]

So just an FYI, the reason you are not seeing results with neem oil is because you may not be using cold pressed. If your label says “hydrophobic extract” it is just like any other kitchen oil. The active ingredient, azadirachtin, has been removed and sold as another product. Azadirachtin is actually the pest killer. The azadirachtin is present when you use cold pressed neem. HUGE difference in pest control results.

You called it.
70% clarified hydrophobic extract of neem, 30% "other" ingredients.

I'm not wasting the rest of the bottle, but I think I'll shop around for the cold pressed like you said.
Thanks for the tip off!